We met with Marcial Bardolet at the Hotel Nixe Palace, a privileged spot by the sea where we sat down to talk about one of the Mediterranean’s greatest natural treasures: Posidonia oceanica. We would like to thank the hotel for offering us this inspiring setting, which also holds a special meaning for our guest.
Marcial reminds us that the Nixe was the ship of Archduke Luis Salvador of Austria, a pioneer in documenting and sharing the richness of the Mediterranean. An avowed admirer of his work, Marcial finds in this legacy a constant source of inspiration in his daily mission to protect the Balearic Sea.
With this context in mind, we began a conversation that highlights the importance of posidonia, its role in the health of the ecosystem, and the ongoing efforts to protect it.
Marcial is clear: posidonia is the jewel of the Mediterranean. “It’s not an algae, as many people believe, but a plant that forms true underwater forests,” he explains. These meadows are responsible for the transparency of Balearic waters, the region’s biodiversity, and its valuable fishing resources. “It’s the number one habitat, because it not only gives life within the sea, but also outside: thanks to posidonia, we have such beautiful beaches and crystal-clear waters.”
One of the most visible effects of posidonia is water transparency. “When the waters are clear, sunlight penetrates deeper, allowing posidonia to grow down to 40 meters,” says Marcial. This creates vast green meadows that, at the end of summer, renew their leaves like a deciduous forest. “The dry leaves wash up on the coast, but that doesn’t mean the plant is dead—it’s regenerating. It’s part of its natural cycle.”
Overall, posidonia in the Balearic Islands is in good condition, partly because the archipelago is not highly industrialized. However, there are two major threats: wastewater discharges—especially in Palma Bay—and the impact of anchors from large vessels.
“For years, anchoring pressure was enormous, but thanks to collaboration between the Government, private companies, and the nautical sector, we’ve managed to greatly reduce the impact,” Marcial notes.
Since 2018, the Balearic Islands have had the strictest legislation in the Mediterranean: anchoring on posidonia is prohibited, regardless of vessel size. “In France, for example, the ban only applies to vessels over 24 meters. Here, protection is absolute.”
To enforce the regulation, several tools are combined:
- Official cartography and mobile apps that help identify sandy areas.
- Eco-friendly mooring fields, which avoid the use of anchors.
- A surveillance service with 19 vessels advising captains on how to anchor correctly.
The results are encouraging: “Ninety-five percent of vessels now anchor much better than before. Especially large yachts, which use apps and digital charts. Awareness has improved enormously.”
Innovation is transforming the protection of posidonia. Today, satellites, drones, and underwater sonars are used to map the seabed with great precision. “The goal is to create a marine digital twin of posidonia in the Balearic Islands that can serve as a model for the entire Mediterranean,” Marcial affirms.
The future plan includes installing more eco-friendly mooring fields in high-pressure areas, especially in Ibiza, Formentera, and specific parts of Mallorca and Menorca. “We want anchoring without damaging posidonia to always be possible. It’s also important that prices remain accessible for the local population, with fees adapted to vessel size and use—even with daily passes for small boats.”
The posidonia surveillance service works year-round to raise awareness among captains and crews. “Direct contact at sea is invaluable, but we also run preseason campaigns in ports along the French Riviera, Valencia, and Catalonia. We want the message to reach them before they arrive here.”
The change is evident: many captains now call the service directly to ask where they can anchor or how to use the apps. “Before, it was citizens who reported violations; now it’s captains who seek us out to make sure they’re anchoring correctly.”
Society also plays a key role. Diving clubs have been collaborating in scientific monitoring for more than 20 years, collecting data on the conservation status of posidonia meadows.
Additionally, the Aula del Mar in Palma has become an educational reference: “Every year, thousands of schoolchildren visit. Twenty years ago, nobody knew what posidonia was; today, if you ask in a classroom, most kids raise their hands. That guarantees long-term conservation.”
The Mediterranean is one of the fastest-warming seas. Above 28ºC, posidonia enters thermal stress. “It’s concerning, because we’re seeing more and more marine heatwaves,” Marcial admits.
At the same time, posidonia is a powerful ally in the fight against climate change: it captures carbon far more efficiently than a tropical forest and protects the coast from erosion. “Eighty percent of the sand on our beaches comes from tiny organisms that live in posidonia. Without it, we would lose beaches and, with them, much of our cultural and tourism identity.”
The Balearic Islands are pioneers not only because of regulation but also due to social involvement. “Here, there’s citizen, scientific, and business awareness that doesn’t exist in every country. That balance has been key.”
The Balearic model is already being replicated in other regions thanks to the Mediterranean Posidonia Network, which connects governments, NGOs, and research institutions. “We’ve had visits from Turkey, Tunisia, and France, all eager to learn from what we’ve achieved here.”
Is it possible to replant posidonia? Marcial explains that it’s a very slow process: “The natural recovery of a destroyed meadow can take up to 100 years.” For this reason, he stresses the importance of passive restoration: removing impacts before they occur. “Eliminating the impact is immediate; replanting on a large scale is almost impossible.”
Marcial’s message is clear: “The conservation of posidonia is a shared responsibility. Governments, the nautical sector, companies, and citizens must all row in the same direction. Only then can we ensure that future generations continue to enjoy these crystal-clear waters.”
From Lantimar, we would like to thank Marcial Bardolet for sharing his knowledge and commitment to protecting posidonia, as well as the Hotel Nixe Palace for providing the perfect setting for this inspiring conversation.
Posidonia is not just a marine ecosystem: it is the essence of the Balearic Islands, the reason behind their crystal-clear waters, white sand, and biodiversity. Protecting it means protecting our Mediterranean—and together, with awareness and action, we can achieve it.